Silkworm (Bombyx mori L.) is a larva belonging to Bombycidae which was first recorded in <Sinnongbonchogyeong()>. Silkworm powder has been widely used for diabetics in folk remedy. It was confirmed by animal test and clinical test that silkworm powder had the activity of lowering blood sugar by inhibiting the activity of intestinal α-glucosidase and also had the activities of alleviating hepatitis and liver cirrhosis and of inhibiting the generation of ROS (reactive oxygen species) and of increasing the activity of ROS scavenger enzyme. In addition to the studies on silkworm powder, studies about various effects of hydrolysates of silkworm cocoon such as fibroin and silk sericin confirmed that such hydrolysates also had the activities of suppressing ROS in liver tissues, anti-diabetes, lowering blood cholesterol, and alcoholysis, etc. Silkworm is an insect that has a relatively big body volume, suggesting that it is easy to obtain hemolymph therefrom. Moreover, chemical composition of silkworm hemolymph is simpler and well-studied (Higashihash et al., 1991), compared with FBS (fetal bovine serum), so that it favors for the separation and purification of useful materials from cells. Well preserved genealogical characteristics is also advantage of silkworm hemolymph, suggesting that there is hardly difference in between lots as long as it is produced from the same silkworm genealogy.
According to the recent development in industry and in modern medicine, radiation and radioisotope are widely being used. As national income increases, the interest in personal health is also increased. Accordingly the use of radiation in the field of medicine is increased as well. In particular, radiation and radioisotope have been widely used in diagnosis and treatment of diseases in the field of medicine, which might affect health of patients and radiation handling workers. Radiation increases reactive oxygen species (ROS) in the inside of human body and the increased ROS results in the damage of DNA, protein, and cell membrane and further affects hematopoiesis system. So, studies and attempts to develop radioprotective agents are actively under-going. As radioprotective agents to prevent biological damage caused by radiation, such synthetic materials as WR-2721 (amifostine) and WR-638 (aminoethylphosphorothioate) have been developed. However, they demonstrate a strong toxicity and are highly expensive. Therefore, it is strongly requested to develop a natural radioprotective agent with less side effects.